More than 745,000 students were expected on Thursday to join in the country's largest school music participation program, Music: Count Us In.

It involves students learning the same song for Celebration Day, when they sing it at the same time.

Warners Bay High music teacher Emma Husband said this year's song was written by former Novocastrian John Foreman and called We Are.

"It was about having the confidence to do anything and promotes self esteem in kids," she said.

"It was really exciting. We call it the song that stops the nation.

"We were all on a high and the kids left saying 'That was awesome'.

"It fosters music education throughout all stages."

She said Warners Bay High had participated in the program for a number of years, but this was the first time it had collaborated with Valentine Public School for activities in the lead up to the simultaneous singalong.

This included Warners Bay's concert band and choir and Valentine's senior concert band and choir combining to perform a song from How To Train Your Dragon.

They also performed a series of shows throughout the day for the rest of Valentine's more than 500 students.

Warners Bay's choir performed I Was Only 19, Rocket Man and Zero to Hero and its band performed the Blue Brothers Revue and The Greatest Showman revue.

Valentine performed Groovee and See You Again.

Lambton High also held an event and invited students from Muswellbrook High and New Lambton, Lambton, Wallsend South, Largs and Hamilton South public schools.